1. Field of the Invention
The present invention relates to a bending block for bending the rolls of cluster roll stands. The bending block is rigidly connected on both sides of the chocks of the pair of rolls to be bent to the windowed housing posts of the roll housing or to units for the horizontal stabilization of the rolls. The bending block has bending jaws which are slidably guided in both bending directions and are driven by means of piston-cylinder units. The chocks or the units for horizontal stabilization have pressure receiving surfaces and the bending jaws have pressure contact surfaces which act on the pressure receiving surfaces in one or the other bending direction.
2. Description of the Related Art
In known embodiments of the bending blocks of cluster roll stands with pairs of work rolls and back-up rolls acting on the work rolls, the bending blocks are guided vertically and have horizontal slots with a rectangular cross section which can be slid onto correspondingly shaped, rectangular stop projections provided on the chocks of the work rolls. When the piston-cylinder units driving the bending blocks are actuated, bending forces are applied on the chocks, so that a bending movement is imparted on the chocks and the chocks are moved either toward each other or away from each other. During the rolling operation, the bending jaws for the upper and the lower chocks together follow the vertical movements of the work rolls produced in the work rolls through the balancing devices of the back-up rolls.
The necessary and unavoidable play between the horizontal slots and the stop projections engaging in the horizontal slots resulting from the guidance between the pressure contact surfaces of the slots and the pressure receiving surfaces of the stop projections impairs an accurate adjustment of the bending forces particularly when very small bending forces are to be applied and also when the direction of the bending forces to be applied is reversed (zero pass).